ES window for long vs short 7mm/30 cal

[300SALRH]

Although recoil plays a role, I assume the reason why f-class open prefer the short mags is its wide tune window for low ES? With a 2000m rifle in mind, would you suggest sticking with the short mags or consider something a little bigger and longer in a 7mm or 300?

 

[Titan]

I would guess the conventional wisdom is the 20 shots for record format is the limiting factor. The larger magnums are burning too much powder in too short of a time period dumping heat into the barrel, also no muzzle brakes are allowed so fatigue can become a factor. I never tried anything larger than a 7-300wsm in F Class and I wasn't impressed with the 7-300 vs the .284 based cases with regards to vertical dispersion over 20 rounds.

I have no experience shooting 2000m what's the format for the competition?

 

[No i deer]

Is there an exact science to why these magnums get verticle dispersion or just theory's.
I too have a 7mm 270 and had terrible vertices with the 7mm 190gr Atips at a recent match..
After 3 matches I switched back to the 180gr hybrids and that cured it.
I will try the Atips in my other 7mms to see if it does it in them